The purpose of video stabilization is to remove undesired image motion from a video. Such undesired image motion typically originates from shaky motion of the camera that is used to capture the video.
In many applications the computational resources are limited and/or a stabilized real-time representation is required. One example is when analyzing video from aerial reconnaissance systems where there is of utmost importance to remove undesired motion in videos to enable remote control and to provide high quality videos. In such systems, there is a long distance between camera and image object and the objects are typically three-dimensional, which gives different requirements as compared to e.g. production surveillance systems or monitoring systems for microscopes. Moreover the design of an aerial reconnaissance system is always a tradeoff between performance and size. Increasing the image performance often means increasing the size of the payload which is not always possible.
Thus, in current video stabilization systems, a fairly long sequence of sequential image frames of the video is analyzed to compensate one single image frame which adds at least one frame delay to perform the stabilization. One example of such video processing is described in EP1377036.
Moreover, the analysis comprises an estimation of the global motion with determination of a global motion model by assuming a geometrical transformation from one image frame to another and by aligning pair-wise consecutive image frames of the sequence. Thereafter local motion estimation is performed in order to describe the motion that deviates from the global motion model. It is assumed that the intentional motion in the video is slow and smooth and accordingly any high frequency components are removed. Thereby a smoothening of the motion is accomplished.
In view of the foregoing, it is appreciated that the video stabilization of today has a high computational complexity and the video latency due to the video stabilization is substantial.